SCHEDULE II - VALUATION AND QUALIFYING ACCOUNTS (Details) - Allowance for Doubtful Accounts - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance		$ 6,601	$ 4,553	$ 3,985
Charged to Costs and Expenses		14,689	9,417	4,232
Charged to Other Accounts	[1]	(235)	(102)	(41)
Deductions	[2]	11,277	7,267	3,623
Balance		$ 9,778	$ 6,601	$ 4,553

[1] Recoveries of accounts previously written off and minor adjustments.

[2] Uncollectible accounts written off.